This invention relates to flexible support stands or posts which are typically used for supporting items such as lamps, tools, microphones, cameras, faucets or other items. In the past, flexible supports have been limited in length due to the weight of the item being supported and the weight of the support itself causing the joints of the support to lose the position in which they were set. Such loss of joint positioning results in drooping of the support and of the item supported. Another limitation of previous flexible supports is the inability of the support to be easily returned to a position where all segments in the flexible support form a straight line. The present invention provides a multi-segmented flexible support that overcomes these limitations.
Flexible supports for lamps or other lightweight tools have typically been constructed of either a semi-rigid shaft that allows for bending and positioning of the supported item, or of a series of variously styled joints that result in an effective flexibility of a series of rigid segments. Early inventors made use of swiveled ball joints to achieve a universal range of lamp or tool positioning. U.S. Pat. No. 1,186,428 to Newman (1916) described a lamp bracket using a series of ball and socket joints to allow flexible positioning of the lamp. Its externally routed power cord would have exposed the wire to possible damage during use, however, this idea does effectively illustrate the basic approach built upon by a number of similar, subsequent ideas.
In U.S. Pat. No. 936,379 to Stevens (1909), the approach to routing the lamp""s power cord through the center axis of the flexible support is disclosed. In this idea, a xe2x80x9cballxe2x80x9d and xe2x80x9cthimblexe2x80x9d bracket arrangement provides flexibility of the support. An additional useful aspect of this idea is the use of a tension spring which runs along the length of the support""s hollow interior and keeps the system stiffer, yet still flexible. However, the overall useful length of this device is limited in part by the balance between the tensioning spring""s effect on joint tightness versus the loading placed on the device by the supported lamp, as well as that of its own weight.
U.S. Pat. No. 1,279,803 to Watson (1918), describes a similar axial spring-tensioned support. This device uses ball and cone-shaped segments of gradually decreasing size with proximity to the lamp end of the support. The decreasing size, and therefore decreasing weight, of the support""s segments allows for greater useful length, however the support length is still limited in part by the balance between the tensioning spring""s joint stiffening effect and the loading imposed by the supported lamp.
More recent approaches to flexible tool or lamp supports make use of conjoined multiple ball and socket segments. U.S. Pat. No. 5,398,176 to Ahuja (1995) and U.S. Pat. No. 5,521,803 to Eckert, et al. (1996) both use ball and socket joints that rely on a friction fit to maintain joint stability. As with previous similar devices, the overall useful length of the support is limited due to reliance solely on this friction fit of the joint. Also, none of the other devices referenced have a means to quickly and easily return the support to a true axially straight alignment following use.
The present invention provides an improved, flexible support assembly comprised of a series of ball and socket jointed segments. The ball of one segment fits into the socket of a conjoining segment and the resulting joint is held in place by friction that comes from three different sources. The first source comes from the ball and socket themselves. In their working positions the outer surface of the ball and the inner surface of the socket provide a source of friction. Secondly, a radial compression device around the socket creates more friction between the ball and socket. The radial compression device can be set to provide varying degrees of friction, within the same support, based on the requirements of the item being supported. Further, the radial compression device automatically adjusts to compensate for lost friction in the joint due to normal wear that occurs over time. Finally, a spring loaded detent plunger in the shaft of each segment pushes against the ball of a conjoining segment thereby creating the third source of friction. When the support assembly is bent into a desired shape by the user the shape is maintained in the present invention without drooping. This is made possible by the three sources of friction acting on the ball and socket in each joint.
After any two segments have been flexed at their associated joint, the segments can be quickly and easily snapped back into a true axially straight alignment. This is accomplished through the use the spring loaded internal plunger detent mechanism which forces a plunger, located toward the socket end of each segment, partially into a hole that is in the top of each ball when the segments are flexed back toward an axially straight alignment.
Accordingly, several objects and advantages of my invention are:
(a) to provide a flexible support for lamps, tools or other items, such as a microphone, camera or faucet, that the user can universally position to a variety of useful orientations, yet be quickly and easily returned to an axially straight configuration after use;
(b) to provide a flexible support for lamps, tools or other items that is designed to be manufactured with various segment lengths to allow for differing effective bend radius needs, depending on the end use of the support;
(c) to provide a flexible support with the option of being manufactured with varied radial compression device tensions on each segment socket, depending on the intended load that the support, or individual support segment, will carry; and
(d) to provide a flexible segmented support assembly of greater useful length than previous flexible supports.